Draft mechanism



Aug. 12, 1958 E. H. BLATTNER DRAFT MECHANISM Filed Dec. 2, 1953 FIG. 1

FIG. 2

Inventor:

3 6 Emil H. Blattner FIG. 3

his Attorney nited DRAFT MECHANISM Application December '2, 1953, SerialNo. 395,649 8 Claims. (Cl. 213-65) This invention relates to draftmechanism and has for its primary object the provision of improved draftmechanism of exceptional capacity.

Another object of the invention is to provide improved draft mechanismwherein the yoke for connecting the draft gear to an associated coupleris formed as an integral part of the housing of the draft gear, wherebythe space normally occupied by the yoke in a draft gear pocket is savedand utilized for increasing the lateral dimensions and, correspondingly,the capacity of the draft gear.

An additional object of the invention is to provide improved draftmechanism wherein, by combining housing and yoke in a single structure,a plurality of pairs of friction shoes and their associated spring meansare enabled to be housed in the housing and act thereagainst foreffectively cushioning excessive impacts.

A further object of the invention is to provide improved draft mechanismof high-capacity for use with a proposed A. A. R. Type F coupler,wherein a front follower, containtable within a yoke formed integrallywith the housing of the draft gear, is of such arrangement andconstruction as to be effectively centered under buifing forces.

Other objects and advantages of the invention will appear hereinafter inthe detailed description, be particu larly pointed out in the appendedclaims, and be illustrated in the accompanying drawings, in which:

Figure 1 is a side elevational view, with portions broken away and shownin vertical section, of a preferred embodiment of the draft mechanism ofthe present invention.

Figure 2 is a plan view, with portions broken away and shown inhorizontal section, of the draft mechanisms of Figure 1, the coupler andconnecting pin having been removed.

Figure 3 is a vertical sectional view taken along the lines 3-3 ofFigure 2; and

Figure 4 is a vertical sectional view taken along the lines 44 of Figure1, with the coupler removed.

Referring now in detail to the drawings, in which like referencecharacters designate like parts, the improved draft mechanism of thepresent invention is designed particularly to fit within an A. A. R.standard draft gear pocket and to have a capacity in excess of 30,000ft. lbs., far above the present A. A. R. standard of 18,000 ft. lbs.Although the standard dimensions for such a draft pocket are 12%" x 12/2" x 24 /8", the dimensions for the draft gear, itself, when a separateyoke is used, are reduced to 9 x 12 /2" x 24%, the difference in thelateral dimensions affording space within the associated center sillsfor the accommodation of the yoke conventionally employed fortransmitting draft forces to the draft gear. As will become evident asthe description proceeds, the conventional separate yoke is heredispensed with and the yoke, instead, is combined or made integral withthe housing of the draft gear, thus saving for the draft gear the spacenormally alotted to the yoke and Patent 0 Patented Aug. 12, 1958enabling the housing to be increased in lateral dimensions tosubstantially the full size of the standard pocket, 12 /2 x 12 /2", thisincrease in volume being put to effective use to correspondinglyincrease the capacity of the draft gear.

In its illustrated form, the draft mechanism of the present invention iscomprised, as mentioned, of a combined or integral yoke and housingunit, designated as 1, which is especially designed to supplant aseparate vertical yoke, and the draft mechanism will be so described. Itwill be understood, however, that the draft mechanism may as well beused to replace a horizontal yoke, in which case, the draft mechanism,as here described, would be turned on its side.

Serving both to house the cushioning elements of the draft gear and asthe rear portion of the yoke by which draft forces are transmitted tothese elements, the housing or housing portion 2 of the combined unit 1is formed longitudinally of top and bottom walls 3, and connecting sidewalls 4, the several longitudinal walls being connected at their rearends by an integral end wall 5 closing the rear or inner end of thehousing. The side walls 4 of the unit end somewhat forward of itslongitudinal midpoint. However, the top and bottom walls 3 extend thefull length of the unit and assume, forwardly of the side walls, theconfiguration of the forward portion of a conventional yoke, theparticular configuration varying with the type of coupler with which thedraft mechanism is to be used. The forward extension of the top andbottom walls 3 thus provides a pair of vertically spaced arms 6 integraland merging at their rear ends with, but narrower than, their respectivetop and bottom walls. When applied, as in the illustrated embodiment, toa proposed A. A. R. Type F coupler, only the butt or rear portion 7 ofthe shank of which is shown, the arms 6 are connected adjacent theirforward extremities by a pair of transversely spaced upstanding orupright webs 8 which, with the arms, define a hooded opening 9 for thereception of the coupler. The coupler is connected to the combined unit1 in the same manner as to a conventional yoke, by a vertical pivot pin10 which rides at either end in longitudinally elongated slots 11 in thearms 6.

Rearwardly of the arms 6 the housing 2 is substantially square incross-section and provides, interiorly of its several walls, an innerpocket, cavity or recess 12, bounded or confined at the rear end by therear or end Wall 5 and at all sides or laterally by the longitudinalWalls 3 and 4". The pocket 12 extends the full interior height of thehousing between the top .and bottom walls 3 and opens, forwardly, intothe, in turn, forwardly opening bell-mouth 13 of the housing. Definingthe mouth 13 vertically are a pair of transversely or laterally,vertically directed, oppositely inclined or sloping friction or wedgingsurfaces 14, which diverge or flare outwardly of the housing and each ofwhich extends substantially the full interior height and forms theforward portion of the inner face of one of the side walls 4. Each ofthese friction surfaces 14 is preferably flat and terminates inwardlyofthe housing in an instanding or inwardly directed shoulder or abutment15, the two abutments being aligned transversely of the housing.

Cooperating with the friction surfaces 14 and serving as the friction orwedge elements of the draft gear, are a plurality of counterpart wedgesor friction shoes 16, each having, intermediate-its longitudinal ends, awedging or friction face 17 corresponding in configuration to andconfronting and adapted to frictionally engage one of the frictionsurfaces 14. The wedges 16 are arranged in sets, two of which preferablyare provided, each set comprising a pair of laterally or transverselyspaced wedges, one facing each of the friction surfaces 14. The

shoes of each set are urged into engagement with the friction surfaceson the housing by laterally or transversely acting spring means,preferably in the form of a pair of opposed sets of semi-elliptic leafsprings 18. As mentioned, two sets of wedges and their associated leafsprings are preferred, both for ready production and assembly and toavoid the possibility of sticking in action, as might well occur with asingle pair of wedges, each having a friction face of the extended areanecessary to encompass one of the friction surfaces 14. The preferredpair of sets of wedges are arranged side by side in superposed relation,with two wedges, one of each set, in engagement with and substantiallycovering or encompassing each of the friction surfaces 14.

The wedges 16 initially or normally project or extend forwardly beyondthe mouth 13 of the housing and are held in that position by a lug orabutment 19 outstanding from each of the wedges rearwardly of itsfriction face 17 and overlapping and adapted to interlock with theshoulder at the rear of the cooperating of the friction surfaces 14. Forguiding the wedges in their movement longitudinally of the housing,each' of the lugs 19 is slotted centrally to slidably receive a portionof one of a plurality of ribs 20, each formed integrally with andinstanding horizontally from one of the side walls 4. For the disclosedtwo sets of wedges, a pair of the ribs 20 are provided on each of theside walls, the ribs of each pair being vertically spaced and thecorresponding ribs of the two pairs being coplanar.

Rearwardly or inwardly of their lugs 19 the several wedges 16 end intransversely or laterally directed, preferably planar, end faces 21which are adapted to abut and wipe against or frictionally engage thefront face 22 of a floating follower or follower block 23 common to theseveral wedges, the floating follower being movable longitudinally ofthe rear pocket 12 in the housing. For

cushioning the rearward or inward movement of the float-- ing follower23, and providing the restoring force by which the wedges 16 arereturned or restored to normal position when relieved of a compressiveforce, there are seated in the pocket 12, rearwardly of the floatingfollower, resilient or release spring means, preferably in the form ofsets of double coil springs 24 for maximum capacity, one such springbeing provided for and aligned in tandem with each of the sets of wedges16. Like the sets of wedges, the double coil springs 24 are arranged inparallel, longitudinally of the housing 2, and in superposed relation,with each spring bearing atits rear end against the rear wall 5 and atits front end against the rear face 25 of the floating follower 23.

For centering the springs the floating follower 23 preferably has ateither side a double-bowed rearwardly directed flange 26, the flangestogether being of substantially figure eight (8) shape and affordingvertically spaced spring seats 27, one for each of the double springs24. While not normally necessary, either similar spring seats or othersuitable centering means, if desired, may be provided on the rear wall 5to center the rear ends of the springs. Although not centering the rearends of the springs 24 vertically, the disclosed structure does serve tocenter them laterally through the lips 28 instanding from the rearwardextensions of the wedge-guiding ribs 20, the ribs thus preferablyextending from the shoulders 15 to the rear wall 5 and therebetween,serving as lateral guides for the floating follower 23 as it moveslongitudinally of the housing.

For transmitting bufling and draft forces to the wedges 19 and theirassociated coil and leaf spring elements, there is provided a frontfollower 29 which is straddled by and included vertically between thearms 6 and has a rear face 30 in wiping or rubbing engagement withtransversely directed, preferably planar, front faces 31 of the wedges.

Bufling forces are transmitted directly to the front follower 29 fromthe coupler, the butt 7 of the latter, when a type F coupler, for thispurpose seating in a forwardly directed spherically concave seat orrecess 32, formed centrally in the front follower. Under such forces thefront follower in its rearward movement may tend to angle relative tothe arms 6. To prevent such angling, the front follower preferably isprovided on either side of the recess 32 with a pair of verticallyspaced, forwardly projecting legs 33 which are confined, laterally andvertically, within the arms 6 and have at their forward ends cylindricalsockets 34 engageable with the pivot pin 10 above and beyond the couplerbutt 7. Thus interlocked in buff, both with the coupler through itsconcave recess 32 and with the pivot pin through the cylindrical sockets34 on its legs 33, the front follower is effectively centered andprevented from gouging into the arms 6. In draft, such centering isunnecessary since, then, the front follower is held between the wedges16 and front draft or stop lugs (not shown) fixed to the center sills(not shown) Within which the draft gear is seated.

Whether in buff or in draft, the action of the front follower on thewedges 16 and their associated elements is the same, in both casesforcing the wedges inwardly, both longitudinally and laterally of thehousing, and in process creating friction not only between the frictionsurfaces 14 on the housing and friction faces 17 on the wedges, but alsobetween the front and rear faces 31 and 21 of the wedges and theconfronting faces of the front and floating followers 29 and 23. Duringthis compressive movement, the friction faces and surfaces of the wedgesand housing are maintained in contact by the leaf springs 18, the latteralso adding to the capacity of the draft gear by resisting the lateralcontraction or compression of the wedges and the coil springs 24 aidingby resisting the longitudinal inward movement of the wedges. On releaseof the compressive force, the coil springs 24, as previously mentioned,force the wedges forwardly and restore them to their normal interlockedposition with the housing. In order that the wedges, when in normalposition will remain so, and thus maintain the several components of thedraft gear in assembled relation, both the leaf springs 18 and the coilsprings 24 are preferably placed under initial compression when thedraft mechanism is assembled.

From the above detailed description it will be apparent that there hasbeen provided improved draft mechanism having a combined housing andyoke and, by utilizing in the housing the space normally allotted to aseparate yoke, having a capacity almost double that of the conventionalfriction draft gear. It should be understood that the described anddisclosed embodiment is merely exemplary of the invention and that allmodifications are intended to be included which do not depart eitherfrom the spirit of the invention or the scope of the appended claims.

Having described my invention, I claim:

1. Draft mechanism comprising a housing having a forwardly openingpocket closed at all sides and rear by longitudinal and rear walls ofsaid housing, spaced yoke arms each integral with and projectingforwardly of each one of a transversely spaced pair of said longitudinalwalls for connecting said housing to an associated coupler, outwardlydiverging friction surfaces in said housing and extending between saidlongitudinal walls, a plurality of wedges in said housing and eachhaving a wedging face frictionally engaging one of said frictionsurfaces, spring means between and acting laterally on certain of saidwedges for maintaining said frictional engagement between said wedgesand housing, a front follower straddled by said arms and interposedbetween said wedges and coupler and frictionally engaged by said wedges,release spring means within said pocket inwardly of said wedges andnormally urging said wedges outwardly of said housing, a floatingfollower common to and between said wedges and spring means andfrictionally engaged by said wedges, and means on said wedges andhousing and interlocked in normal position under force of said springmeans for maintaining said draft mechanism in assembled relation.

2. Draft mechanism comprising a housing having a forwardly openingpocket closed at all sides and rear by longitudinal and rear walls ofsaid housing a pair of spaced yoke arms each integral with and extendingforwardly of and substantially coplanar with one of a transverselyspaced pair of said longitudinal walls for connecting said housing to anassociated coupler, outwardly flaring friction surfaces in said housingand extending between said longitudinal walls, a plurality of sets ofwedges arranged side by side in said housing and each including a pairof opposed wedges, one frictionally engaging each of said frictionsurfaces, spring means between and acting laterally on the opposedwedges of each set for urging said wedges into said frictionalengagement with said housing, a plurality of release spring means withinsaid pocket and each aligned with one of said sets of wedges, a floatingfollower between and common to said wedges and release spring means fortransmitting forces therebetween and means on said wedges and housingfor limiting relative forward movement of said wedges and maintainingsaid draft mechanism in assembled relation.

3. Draft mechanism comprising a housing substantially square incross-section, a pair of spaced yoke arms each integral with andprojecting forwardly of each one of a pair of spaced walls of saidhousing for connecting said housing to an associated coupler, outwardlyflaring wedging surfaces in said housing and extending between saidspaced walls, a plurality of sets of wedges arranged side by side insaid housing, each of said sets including a pair of opposed wedges, onefrictionally engaging each of said wedging surfaces, means instandingfrom said housing and slidably received in slots in said wedges forguiding said wedges during longitudinal movement thereof relative tosaid housing, and means within said housing and acting on and normallyurging said wedges outwardly thereof.

4. Draft mechanism comprising a housing, friction means in said housingfor cushioning longitudinal forces applied thereto, spaced yoke armsintegral with and projecting longitudinally beyond said housing andpivotally connectable by pin means to an associated coupler, and a frontfollower interposed between said friction means and said coupler fortransmitting bufling forces therebetween, said front follower beingstraddled by said yoke arms and having a pair of spaced forwardlyextending legs engageable with said pin means on either side of saidcoupler for centering said follower during rearward movement thereofrelative to said housing in response to buffing forces.

5. Draft mechanism comprising a housing fittable in a standard draftgear pocket between center sills and substantailly equal incross-sectional area to the area included between said center sills,said housing having longitudinal walls and a rear wall confining at allsides and rearwardly a forwardly opening pocket therein, a pair ofspaced arms projecting forwardly of said housing and each integral withone of a spaced pair of said longitudinal walls, spaced outwardlydiverging wedging surfaces instanding from opposite of said longitudinalwalls and each extending substantially the full width thereof, opposedwedges in said housing and having wedging faces frictionally engagingand substantially covering said wedging surfaces, spring means betweenand acting laterally on said opposed wedges for maintaining saidfrictional engagement between said wedges and housing, spring meanswithin said pocket inwardly of said wedges, a floating follower withinsaid pocket between said wedges and last named spring means, and meanson said wedges and housing and interlocked in normal position underforce of said spring means for maintaining said draft mechanism inassembled relation.

6. In draft mechanism a draft gear comprising a housing, spacedoutwardly divergent wedging surfaces within said housing and extendingsubstantially the full distance between spaced longitudinal wallsthereof, a plurality of sets of wedges arranged side by side in saidhousing and each including a pair of opposed wedges each having awedging face frictionally engaging one of said wedging surfaces, springmeans acting on said wedges for normally maintaining said frictional engagement between said wedges and housing, lug means on and outstandingfrom each of said wedges and each engageable with abutment means on saidhousing for limiting outward movement of said wedges relative thereto,and rib means in and extending longitudinally of said housing and eachinstanding form a wedging surface-carrying wall, each of said lug meansbeing slotted for slidably receiving one of said rib means and guidingsaid wedges in longitudinal movement thereof relative to said housing.

7. Draft mechanism comprising a housing, a forwardly opening pocket insaid housing and confined at all sides and rearwardly by longitudinaland rear walls of said housing, a pair of laterally spaced yoke armsintegral with and extending forwardly of a laterally spaced pair of saidlongitudinal walls for connecting said housing to an associated coupler,yieldable means in said housing within said pocket, means in andextending forwardly of said housing between said arms for transmittingforce from said coupler to said yieldable means, and means carried bysaid housing for limiting forward movement of said force transmittingmeans relative thereto and maintaining said draft mechanism in assembledrelation.

8. Draft mechanism comprising a housing, resilient means within andconfined on all sides and rearwardly by longitudinal and rear walls ofsaid housing, a pair of laterally spaced yoke arms integral with andextending forwardly of a spaced pair of said longitudinal walls forconnecting said housing to an associated coupler, and means in andprojecting forwardly of said housing between said arms and normallylimited in forward movement relative to said housing for transmittingforce from said coupler to said resilient means and maintaining saiddraft mechanism in assembled relation.

References Cited in the file of this patent UNITED STATES PATENTS1,258,935 OConnor Mar. 12, 1918 1,280,282 Newell Oct. 1, 1918 1,323,787Richards et a1. Dec. 2, 1919 1,470,287 Priebe Oct. 9, 1923 1,488,159Kadel Mar. 25, 1924 1,956,563 Couch May 1, 1934 2,023,000 Barrows Dec.3, 1935 2,141,680 Barrows Dec. 27, 1938-

